Measuring instrument.



S. TROOD.

MEASURING INSTRUMENT.

APPLICATION FILED OCT. 3, 1913.

Patented June 6, 1916.

INVENTOR WITNESSES:

A.TTORNEY UNITED STATES PATENT OFFICE.

SAMUEL TROOIU, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSEELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIAMEASURING INSTRUMENT.

Application filed October 3, 1913.

To all whom it may concern Be it known that I, SAMUEL Tnooo, a citizenof the United States, and a resident of Wilkinsburg, in the county ofAllegheny and State of Pennsylvania, have invented a new and usefulImprovement in Measuring Instruments, of which the following is aspecification.

My invention relates to measuring instruments and particularly tosteam-flow meters.

The object of my invention is to provide a steam-flow meter forswitchboard service that is substantially automatic in its operation.

My copending United States application, Serial No. 793,117, filedOctober 3, 1913, discloses a steam-flow meter that is substantiallyautomatic in its operation but which should be mounted preferably nearthe steam line in which the steam flows that is to be measured. In mypresent invention I provide a U tube for indicating the flow of steamand I provide means for correcting the indication of the steam flow in aconduit in which the pressure and temperature are substantially constantas determined by the U tube for any small variations in temperature andpressure. In order to mount such an instrument on a switchboard, Iprovide an especially constructed electrical measuring instrument thatis supplied with energy which is dependent upon the velocity, pressureand temperature of the steam to be measured.

The single figure of the accompanying drawings is a diagrammatic View ofa steamflow meter embodying my invention.

A Pitot tube 1 that comprises two compartments 2 and 3, is inserted in asteam line or pipe 4, m a manner familiar to those versed in the art,for the purpose of determining the velocity of the steam. Thecompartments 2 and 3 severally comprise a reservoir of mercury 5 and 6,a non-conducting tube 7 and 8 of relatively small cross-sectional areaand a relatively large closed conducting chamber 9 and 10. A fluidhaving a relatively high resistance is contained in the non-conductingtubes 7 and 8 for purposes hereinafter more fully set forth. Forindicating the readings of the various tubes, I provide an electricalmeasuring instrument 11 comprising a two-pole magnetizable member 12that has two field windings 13 and 14 on one leg and two field windings15 and 16 Specification of Letters Patent.

Patented June 6, 1916.

Serial No. 793,118.

. 0n the other leg thereof, an armature 17 with an armature winding 18thereon and a commutator cylinder 18. The reservoirs 5 and 6 of thePitot tube 1 are connected together electrically by a conductor 19 thatis also connected, through a battery 20, to the field windings 13 and14. The field windings 13 and 14 are wound with their convolutions inopposite directions, in order that the magnetic flux set up bythewinding 13 shall oppose that set up by the "winding 14. The fieldwinding 13 is connected in series relation to the field winding 15 toconstitute a circuit from the battery 20 to the conducting chamber 10,while the field winding 14.

is connected in series relation to the field winding'16 to constitute acircuit from the battery 20 to the conducting chamber 9. The fieldwindings 15 and 16 are so wound that they induce magnetic lines of forcein opposite directions in the magnetizable member 12. From theforegoing, it will be seen that the windings 13 .and 15 are connected tooppose the windings 14 and 16.

A U tube 21 is inserted in the steam line 4 and comprises a reservoir22, a non-conducting tube 23 of relatively small cross-sectional areaand a relatively large conducting chamber 24. Around that part of thetube 21 that projects into the steam pipe 4 is wound a resistor 25. Theresistor 25 is connected in a circuit comprising the battery 20, thearmature winding 18, a variable-resistance resistor 26, a secondvariable-resistance resistor 27 and a high-resistance fluid 28 that iscontained in the tube 23. The high-resistance fluid 28 is forcedupwardly by the mercury 29 contained in the reservoir 22 when thepressure increases in the steam line 4.

Since the quantity of steam that traverses a conduit depends upon itsvelocity, pressure and temperature, I have provided a meter, ashereinbefore stated, that responds to these variables. I have alsoprovided adjusting means for the instrument.

'lVhen no steam traverses the pipe 4, there is no difference of pressurein the tubes 2 and 3 and the mercury in the reservoirs 5 and 6, and,likewise, the relatively high-resistance fluids in the tubes 7 and 8-will remain on the same level, and, since the resistances of the twocircuits are equal, the same exciting current will fiow through all thefield windings. Thus, no resulting magnetic lines of force will traversethe air gap between the field magnet poles of the magnetizable member12. However, should steam traverse the pipe 1, in a direction as shownby the arrow, a difference in the resultant pressure will cause themercury, or other conducting liquid, to stand at a higher level in thetube 8 than in the tube 7, which difference is proportional to thesquare of the velocity of the steam flowing. When the mercury rises inthe tube 8 higher than in the tube 7, the resistance in series with thefield windings 13 and 15 is lessened, by reason of the shorter column ofhigh-resistance fluid, and the current flowing through the same isincreased to cause magnetic lines of force to be set up in themagnetizable member 12 in accordance with the velocity of the steam. I

The current that traverses the armature is adapted to vary in accordancewith the pressure and thetemperature of the steam because the resistanceof the resistor 25 and the resistance of the fluid 28 in the tube 23 arevaried when the temperature and the pressure vary. When the pressureincreases, the mercury rises in the tube and decreases the length of thecolumn of high-resistance fluid, thus causing more current to flowthrough the armature winding 18. However, when the temperature of thesteam increases, the resistance. of the resistor 25 increases and thusdecreases the current in the armature winding 18 in accordance with theincrease in temperature. Therefore, the armature 17 will rotate inaccordance with the velocity, the pressure and the temperature of thesteam. Since the quantity of steam to be measured depends upon thevelocity, pressure and temperature, the rotation of the armatureindicates the quantity of the steam traversing the pipe 4.

I provide variable resistors 26 and 27 for controlling the current inthe armature winding 18,to adjust the speed of the instrument. One ofthe resistors may be used for calibrating the instrument for varioussizes of pipe and the other for calibrating the instrument in order thatit may indicate in various units. The conducting chambers 9, 10 and 25are relatively large with respect to the volume of the tubes 7, 8 and 23in order that the compression therein may not aflect the operation ofthe device to any material degree.

I desire it to be understood that changes may be made in the actualconstruction of my invention, for the purposes of simplifying thedesign, that will not depart from the spirit of same as set forth in theappended claims. i

I claim as my invention:

1. A steam-flow meter comprising a plurality of U tubes severallycontaining a relatively low-resistance fluid and a relativelyhigh-resistance fluid, the resistance of the said fluids being adaptedto vary with the velocity and the pressure of the steam to be measured,a resistor the resistance of which is responsive to the temperature ofthe steam, a measuring instrument, and means controlled by the saidtemperature-responsive means and the resistance of the said relativelyhigh-resistance fluids for actuating the said measuring instrument.

2. A fluid meter comprising a plurality of U tubes severally containinga relatively low-resistance fluid and a relatively highresistance fluidin one arm thereof, said tubes being so disposed as to cause theresistance of the fluids to vary with the velocity and pressure of thefluid to be measured, a measuring instrument, and means controlled bythe relative resistances of the said high-resistance fluids foroperating the r said measuring instrument.

3. A fluid meter comprising a plurality of U tubes severally containinga relatively low-resistance fluid and a relatively highresistance fluidin one arm thereof, said tubes being so disposed as to cause theresistance of the fluids therein to vary with the velocity of the fluidto be measured, a measuring instrument, and means controlled by therelative resistances of the said highresistance fluids in the said tubesfor operatv ing the said measuring instrument.

4:. In a fluid flow meter for a steam conduit, the combination with aplurality of tubes having orifices opening into the con duit, reservoirscontaining mercury, nonconducting tubes attached to the reservoirs withconducting receptacles thereon, said non-conducting tubes containing arelatively high-resistance fluid, one of the said orifices pointing inthe direction of the steam flow, one opposite to the direction of flowand another perpendicularly to the direction of the flow of the steam tobe measured, a resistor mounted adjacent to one of the orifices, ameasuring instrument, and means controlled by the resistance of theresistor and the resistances of the relatively highresistance fluids foroperating the measuring instrument.

5. A steam-flow meter comprising a plurality of tubes severally havingreservoirs containing mercury and non-conducting tubes attached theretocontaining a relatively high-resistance fluid, a resistor exposed to thesteam to be measured, an electrical measuring instrument, and a sourceof electromotive force controlled by the resistance of the resistor andthe relative resistances of the relatively high-resistance fluids foroperating the measuring instru ment.

6. A fluid meter comprising a plurality of tubes severally havingreservoirs containing mercury and non-conducting tubes attached theretocontaining a relatively high-resistance fluid, said tubes being adaptedto cause the said high-resistance fluid to assume various lengths in thesaid non-conducting tubes in accordance with the velocity and pressureof the fluid to be measured, an electrical measuring instrument, and asource of electromotive force controlled bv the relative variation inheights of the relatively high-resistance fluids to operate the saidelectrical measuring instrument.

7. In a fluid meter, the combination With a mercury-containingreceptacle and means for transmitting the pressure of the fluid to bemeasured to the said receptacle, of a relatively high-resistance fluidcontained in the said receptacle, the resistance of the saidhigh-resistance fluid being dependent upon the displacen'ient of themercury in the receptacle. an electrical measuring instrument, and asource of current connected between the said instrument and the saidreceptacle, said instrument being controlled by the change in theresistance in the said high-resistance fluid.

8. A steam-flow meter comprising a plurality of U tubes severallycontaining mercury and a relatively high-resistance fluid in one armthereof, the heights of the highresistance fluids adapted to vary inaccordance With the change in velocity and pressure of the steam to bemeasured, a resistor having a resistance dependent upon the temperatureof the steam, a measuring instrument, and means controlled by theresistance of the temperature-controlled resistor and the heights of therelatively high-resistance fluids in the several tubes for operating thesaid measuring instrument to indicate the quantity of steam beingmeasured.

9. A steam-flow meter comprising a plurality of U tubes severallycontaining a relatively low-resistance fluid and a relativelyhigh-resistance fluid in one arm thereof, the resistance of the saidhigh-resistance fluids being adapted to vary with the change in velocityand pressure of the steam to be measured, means responsive to thetemperature of the steam, a measuring instrument, and means controlledby the said temperature-responsive means and the resistance of the saidrelatively high-resistance fluids for actuating the said measuringinstrument.

In testimony whereof, I have hereunto subscribed my name this 22nd dayof Sept. 1913.

SAMUEL TROOD.

lVitnesses B. B. IIINES, M. C. Mnnz.

